Airplane flap and ground contact control means therefor



Feb. 2, 1 954 V. J. BURNELLI AIRPLANE FLAP AND GROUND CONTACT CONTROL MEANS THEREFOR 3 Sheets-Sheet 1 Filed Aug. 10, 1948 R m N E V W Emmi I Barfly/Ii ATTORNEY V. J. BURNELLI Feb. 2, 1954 AIRPLANE FLAP AND GROUND CONTACT CONTROL MEANS THEREFOR Filed Aug. 10, 1948 '3 Sheets-Sheet 2 INVENTOR Zhzm/Jfiamz/li ATTO R N E Y Feb. 2, 1954 v. J. BURNELLI 2 668927 AIRPLANE FLAP AND GROUNDCONTACT CONTROL MEANS THEREFOR Filed Aug. 10, 1948 3 Sheets-Sheet 5 IN V EN TOR.

A "'0 R/VEYS Patented Feb. 2, 1954 UNITED STATES PATENT OFFICE AIRPLANE FLAP AND GROUND CONTACT CONTROL MEANS THEREFOR This invention relates to a device for rapid reduction in the lift of an airplane immediately following landing contact.

With an airplane of conventional type landing gear equipped with high lift full span flaps which at ground attitude present a high angle of attack and maximum lift to the wing system, it is considered of landing benefit to release the excess lift produced by the flaps at the moment of ground contact thereby increasing the percentage of the aircraft borne by the wheels for better brake action and to prevent the tendency to bounce or remain airborne when landings are made at comparatively high speed which is usually necessary for best control in gusty air conditions. v

The present improved'arrangement is as applied to a Burnelli lifting fuselage type equipped with a flap attached at the fuselage trailing edge section. A further benefit of this arrangement as applied to this type of airplane is that the flap can be used at high angles for maximum lift up to 60 in which position there would not be sufficient clearance from the ground unless the entire under carriage of the airplane was raised.

The release arrangement forming part of'this application providesfor returning the flap to normalv take off position on ground contact. This release comprises an extension contact shaft which extends beyond the trailing edge of the flap and which makes advance contact with the surface to operate a mechanism that is related to the flap drive system and releases the positive drive of the flap so that by air and spring pressure it will rapidly return to neutral. This action of the flap release is synchronized with the operating valve or means for the manual opening of the wing flaps by the pilot. On ground contact of the extension shaft the fuselage flap snaps closed moving the hydraulic valve and reversing the oil flow in the wing flap cylinders so that they return to neutral at reduced speed. No ground clearance problem exists in the case of the wing flaps as with the fuselage flap. The synchronized action for releasing the wing flaps to a closed position also brings the operating cylinder or mechanism for the fuselage flap back to normal position where it engages the ratchet slot required for the release means so that when the pilot operates the lever for lowering the flaps all flaps move to the down position simultaneously. While the fuselage flap is primarily intended for high lift, it

can alsobe adjusted to various degrees of angular position to trim the airplanefor varied C. G. position when not employed for maximum lift landing requirements.

It is assumed that the lift will be reduced about 40% when the fuselage and wing flaps are rapidly closed within a few seconds after ground contact and that this reduction of lift will provide the main advantages that are achieved through the employment of a tricycle or negative type landing gear in which case the lift of the wings is relieved by the airplane assuming a negative angle or zero lift point of the wings during the ground roll following landing.

In connection with this application there is also provided a high lift device employingfull span wing flaps and equipped with spoiler .type lateral control means combined with the lift increase arrangement. This type of lateral con.- trol to make practical the employment of full span wing flaps provides for the angular operation of a portion of the trailing edge shroud which is necessary for the development, of the proper wing flap slot contour for maximum lift.

A section of this trailing edge shroud for the required span of the spoiler control system is hinged forward of the trailing edge slot so that when the spoiler is operated it disturbs the proper slot contour airflow opening developing turbulence and. air deflection which will destroy the high lift of the Wing with the flap extended givingmaximum control effect at slow speeds with open slot. At high speeds when the flap is closed the lateral rolling movement is not as critical and the spoiler operates with an applied down pressure and deflection upward to spoil the lift of the wing over the area covered by the spoiler thereby providing a down pressure on theairplane wings to effect lateral rolling moment correction. a

Combined with this lateral control full span flap spoiler system means for providing lift increase to the lowered wing to co-act with the spoiler for increased rolling moment is provided also for increasing the drag of the wing opposite to that of the wing lift being neutralizedby the spoiler to counteract the yaw or turning tendency created by the spoiler drag. This consists of a synchronized slot controller to intensify and regulate airflow through entering edge wing slots when in the open position for maximum lift increase provides greater air drag and to a degree neutralizes the yaw, or turning caused by the force to relieve operating pressure.

The slot controller valve or vane tothe trailing portion of fuselage 1.

This lift increase slot controller is provided with a compensatin drive inter-connected through the pilots control wheel. A drive shaft connected to the spoilers at opposit wing tips operates the high lift entering edge slot vane which opens through levered arrangement on the wing opposite the spoilers. The slot vane floats in theslot'opening. and hasno aerodynamic effect to increase. the lift on the side on which the spoiler is in action. In combination with this co-ordination of control, means is provided for varying the opening of the high lift wing flap slot for difierent degrees of angular'motion and slot opening. This is provided by springpressure means located in the spoiler-driveshaft. When the wing is closed for high speed attitude the spoiler which forms the slot duct in part re'- mains in closed contact with the flap upper surface and compensating motion for operating the entering edge slot controller is permitted by spring, means in the drive shaft allowing sufiicient movement through the drive differential leverage. As the wing; trailing edge slot opens the spoiler moves d'ownwardthrough this spring pressure and varies the degree of opening and improves the direction of air flow over the flap for maximum lift.

With the foregoing general objects, features andresults in view, as well as certain others which willbe apparent from the following explanation,

the invention consists. in certain novel features design. construction-,. mounting and combination of. elements, as will, be. more. fully and particularly referred to and specified hereinafter. Inthedrawingsz.

, Figure. 1 is a side elevation. showing the trailing. portion of a. Burneili type lifting fuselage having a. flap. and. means for automatically restoring said flap to neutral from the down position. on landing.

FigureZis a partial side elevation of a Burnelli type airplane whose lifting fuselage is provided with. the-flap of Fig. l and. also showing a wing flap Figure 3 is an enlarged side elevation of a wing having a flap;- also: a spoiler and lift increase means adapted for purposes of lateral control; hydraulic system means also appearing. in this view: for fiapoperation, said system interconnecting the fuselage and. win flaps whereby the wing flaps are restored toneutral as a result of the automatic return of the fuselage flap.

Figureeisan enlargediplan. view of the fuselage flan drive shaft and the means-for'releasably associati-ng. the hydraulic system therewith, parts of the elementsbeing broken away.

Figure is a plan: view of the fuselage flap, with parts thereof being broken away, and of. the mechanism. illustrated in Fig; 4.

This application is a continuation in part of pending. application filed by me July 18, 19.45, SenlalNumber 605,802,. now abandoned, for Airplane Elapanda Lateral ControlMeans.

In; Figures 1 and 2 I have used the numeral I toindicate a lifting fuselagezof aBurnelli type airplane whose trailing portion 2 has a shroud 3- whichreceives: a flap 4 that is swinga-bly or rockably. mounted in any conventional manner An arm 6 ispivotally mounted as at. 5 on. bracket 1 which extends from. said. trailing. portion. The arm 5 is jointed. as at 8' to. the respective push-pull rods 81!. and. 9'. The rear rod Sais pivoted at. its opposite end as at I'll to a rocker plate I l., which rocker plate is pivoted at [2 to the trailing edge of the flap 4. An extension element or feeler rod I3 is fixed to the rocker plate and extends rearwardly therefrom in the air stream from the flap t and will therefor produce substantially no drag. The pivot for flap 4 is concentric or coincident with pivot or joint 8 when feeler rod [3 is in its neutral or undeflected position. With the flap in neutral position. the extension. elementwill extend in substantially horizontal position.

The forward push-pull rod 9 which is jointed as at 8 to arm or link 6 is pivotally connected at its opposite end to the lower end of a link or arm 16w having a collar IBb on the upper end thereof, which collar receives and is fixed to shaft I60 so-that rod 9 is hun at its forward end from the link Hia. Shaft 16c pivotally mounts a collar 232 which is integrally formed on one end of acrank arm designated generally by the numeral 23', the crank arm as will be apparent from the description to follow constituting the supporting means'for collar 23m and'it associated elements. I provide a locking pawl M which is fixedat one end as at Ma to. shaft the pawl I4 extending forwardly and provided with a lateral nose Mb on the forward end thereof. A ratchet disc M having a notch l4" formed in the periphery thereof in position to receive the nose lb of the paWl' is provided and is. fixed on flap drive shaft it for rotation therewith. The flapdrive shaft [6 is supported by two or more brackets ifid'which are supported. in any. suitable manner from the fuselage. The flap 4' is operatively connected with shaft ['6 by the levers i8 and I9 whichare. jointed together as at 21!, the lever I8 being pivoted as at II to 2. lug 22 extended from the flap and the lever 19 being. fixed as at (9:1 to shaft l6.

A sprocket wheel [5 is fixed to shaft I 6 for rotation therewith and. said wheel i connected by a chain 3|. with. a further sprocket wheel 32 which. may be operatively associated with an operating. handle 25. by means of a detent 33 engageable in a notch in the sprocket wheel 32.

The hydraulic operating. system. for the. flaps includes the valve 24, and the lines 25 and 2'! which. extend from the. valve. to opposite ends of the oilcylinder. zawmcn is pivotally mounted as at 2-9. The piston stem 38 is engaged by crank arm 23 as clearly illustrated in Fig. 1 of the drawings.

As hereinbefore discussed it is one of the objects of this invention to provide for the operation of wing flaps synchronously with the operation of the fuselage flap 4. In Figs. 2 and 3 of the drawings I have illustrated wing flaps 38 which are operated by an oil cylinder 39 inea'ch wing. 31-, opposite ends of the cylinder bein connected into the hydraulic system by means of pipes 26aand 210; which are connected to pipes 28. and. 21;. respectively. The synchronous operation of the flaps will be hereinafter ex- I plained.

The crank arm. 23- is mounted for pivotal rocking movementv on one end of shaft I6 bymeans of a floating. bearing-23b onshaft Hi.

When an aircraft equipped for automatic synchronous operation of the-wing flaps and fuselage fiap, in accordance with this invention, is landing and feeler It contacts theground thereby rocking rocker plate It, the push rods Ba and 9 are pushed. forwardly about the center 5 and the arm Hid isthereby rocked. to rotate. shaft I60 by means of. collar [6b which. is. fixed thereto. Rotation of. shaft 16c. rock pawl Hi. upwardly out of notch M in ratchet disc M" and the flap 4,

shaft l6 and disc M are free of the hydraulic system. When this condition exists the flap 4 under air pressure, and spring means if desired, will return to neutral or raised position, and in so doin will, through the action of arm l8 and I9, cause rotation of shaft [6 in the directionof the arrow in Fig. 4 of the drawings. Since ratchet disc I4 is fixed to the shaft it will rotate therewith moving notch M" to an upper position. The rotation of shaft 16 by the action of arms l8 and 19 will also rotate the sprocket l5 and control valve sprocket 32 through the action of chain 3| will likewise be rotated and handle 25 will be moved with the sprocket due to detent 33 being in sprocket wheel notch.

In Fig. 3 of the drawings valve 24 i shown in position assumed with the flap depressed, that is line 26 is the pressure line extending to the upper end of cylinder 28 to maintain crank arm 23 in retracted position, and to the forward end of cylinders 39 in the wings. When the shaft it rotates as described the valve 24 is rotated to reverse the fluid flow in the hydraulic system, thus, lines 21 and 21a become the pressure lines and the pistons in the cylinders will move to the opposite ends thereof to return the wing flaps 3.8 to neutral position synchronously with the fuselage flap.

This fluid reversal in cylinder 28 will project piston stem 30 and extend the crank arm 23, rocking it on bearing 23a and rocking or downwardly moving shaft 16c and its associated elements. This rocking movement about shaft [6 will bring the hook I4b of the pawl up and around to the upper position of'notch .l4 and it will fall thereinto again locking the flap control mechanism for depression of the flaps under the pilots control.

In order to depress or drive the flaps down the pilot merely moves the operating handle to the position shown in Fig. 3 whereupon lines 26 and 28a become the pressure lines and the crank arm 23 is retracted, rocking on bearing 23a and since pawl i4 is in the notch in ratchet disc 14', the

disc will be rotated back to the position shown in Fig. 4, rotation of the disc rotates the shaft [6 and the flap 4 will be driven down by arms or levers I8 and I9. It is to be understood that when the pilot moves handle to full line position to drive the flaps downwardly he retracts the detent from the notch in sprocket wheel 32, so that the sprocket wheel is not rotated thereby, then when flap 4 is depressed the sprocket wheel will be rotated until the notch again receives the detent 33.

Increase in lift for the fuselage flap 4 is provided by the slot or gap which opens up between the fiap and shroud as the flap is lowered, this slot receiving augmented pressure flow by means of a controller vane 34, pivoted at 35, that normally lies in slot closing position, but which, as the flap is lowered, opens the entrance to the slot and also serves as a scoop to increase drag and direct air flow through the slot. To this effect the vane 34 is pivotally connected with the flap by a link 36 whereby the movement of the flap to and from neutral and depressed positions are communicated to said vane.

The outspanned wings which extend from opposite sides of the lifting fuselage, one only ap- 3, where also the hydraulic flap operating means is indicated.

For lateral control means, necessary both in normal flight and at times when the airplane is about to make a landing, I provide each wing with appropriate drag means for use when the wing is at the high side, and also with means of increased lift for use when it is at the low side. Thus, what I call a spoiler, indicated at 40, actually is a separated segment of the shroud 4!, and is hinged at 42 so as to be capable of forming part of the shroud in the normal flying attitude of the airplane, or of being raised to the position shown in dotted lines in Fig. 3 to provide drag. If at such time the flap 38 i lowered as for slow landing, thus creating a slot opening between the flap and shroud, holes or a slot 43 through the spoiler will enable a cross flow through said holes to intensify turbulence in the slot thereby assisting to destroy lift of the V wing at the high side.

Mounted on a transverse shaft 44 is a pulley segment 45 which is operated by a cable 46 that extends to the cockpit for actuation by the pilot. Also carried by said shaft 44 are arms 41, 48, the arm 4'! pivotally engaging a rod 49 whose other end is in pivotal engagement with a vane 50 that i pivoted at 5| adjacent a slot 52 located near the entering edge ofthe wing, for the control of said slot. Normally vane 50, as seen in full lines, nearly closes slot 52, and, as will be noted it has two other positions, both shown in dotted lines, one where it closes the slot and the other where it fully open the slot and also serves as a scoop to permit air flow over the wing for lift purposes when the wing is at the low side, to counterbalance the drag afforded the other wing by the raised spoiler at the high side.

It should be appreciated that when the spoiler is elevated to provide drag for the wing at the high side, then vane 5|] on this high side is able to float betweenits position of full and partial closure, but when the vane 50 for the wing on the low side is moved to its full slot open position. The butt or inner end of spoiler 40 is pivotally connected to an actuating rod 54' as at 56. The opposite end of rod 54' is pivotally connected as at 53' to drive arm 48 and the actuating rod is slidably encased by a tube 54. A compression spring 53 lies between an end of the tube and the pivot 53. In consequence, when pulley segment 45 is rotated in one direction, rod 54, which engages the spoiler at 56, is caused to pull the spoiler down into its slot closing position in the shroud, and because of the yield, afforded by spring 53 said spoiler may depress into the flap slot with spring slack while vane 50, influenced by rod 49 is enabled to float between its nearly and fully closed positions with respect to slot 52.

I claim:

1. In an airplane, flaps and flap operating and controlling means, and an extension member pivotally carried on a flap and extending from the trailing edge of the flap in the air stream therefrom when the flap is closed, said extension member and said flap operating and controlling means operatively connected together, said member adapted to make surface contact preceding a landing when the flap is depressed, surface contact of said extension member causing pivotal movement thereof on the flap, and said flap operating and controlling means actuated by the pivotal movement of saidextension: member for permitting closing of the flap.

2; In an; airplane, afuselage flap and operating means therefor, an extension member pivotally mounted on and extending. from said fuselage flap and adapted tomake surface contact preceding a landing when the fuselage flap is depressed; such surface contact by said extension member inducing pivotal movement thereof on the flap,v means for releasing said flap from depressed position for return to normal position, and linkage mechanism operatively connected to said extension. member and said flap release means and positively actuated by said extension member in its pivotal movement induced by surface contact to operate said flap release means.

3. In an airplane, a fuselage fiap and operating. means therefor, an extension member pivotallyv mounted onand extending from said fuselage flap and adapted to make surface contact preceding a landing when the fuselage flap is depressed, such surface contact by said extension member inducing pivotal movement thereof on the flap, releasable locking means-for maintaining the flap in depressed position, means for releasing said flap from locked depressed position for return to normal position including push rods mechanically connected with said extension member and with said releasable locking means and actuable by pivotal movement of the extensionmember to trip said locking means permitting said flap to return to normal position.

4. Ina lifting fuselage airplane, a fuselage flap, wing; flaps and. flap operating mechanism, an extension member pivotally mounted on and extending fromsaid fuselage flap and adapted to make surface contact preceding a landing when the fuselage flap is depressed, such surface contact by said extension member inducing pivotal movement thereof. on the flap, releasable locking means for maintaining the flap in depressed position, means for releasing said flap from locked depressed position for return to normal position including push. rods associated with said extension member and actuable by pivotal movement, thereof totrip-said locking means permitting said flaptoreturn to normal. position, and rotary means actuated by the return of said fuselage flap to normal. position. for simultaneously operating mechanism causing the closing of the wing flaps.

5. Ina lifting fuselage airplane, a fuselage flap, wing flaps and hydraulic flap operating mechanism including a valve operable to reverse the fluid flow for changing the positions of the flaps, anextension. member pivotally mounted on and. extending from. said fuselage flap and adapted to make surface contact preceding a landing when the fuselage flap is depressed, such surface contact by said extension member inducing pivotal movement thereof on the flap, releasable locking, means for connecting the hydraulic system with. the fuselage flap for maintaining said flap depressed, and mechanism operatively connected with the releasable locking means. and the extension member and actuated by thepivotal movement of the extension member to release, the locking means and disconnect the hydraulic system from the fuselage flap for the return of the flap to neutral position, and rotatable means, connected with and actuated by the return of the fuselage flap to neutral position, to operate the valve to reverse the flow of fluid in the hydraulic systemv to cause the Wing flaps to return to neutral position.

VINCENT J. BURNELLI.

References Cited the file of this patent UNITED STATES PATENTS Number Name Date 1,998,487 Burnell'i Apr. 23, 1935 2,070,006, Eaton, J12, et a1. Feb. 9, 1937 2,173,273 De Seversky Sept. 19, 1939 2,276,522 Staufer Mar. 17, 1942 FOREIGN PATENTS Number Country Date 846,337 France June 5, 1939 

